Die casting and pressure molding machines



May 25, 1965 J. H. HOERN DIE CASTING AND PRESSURE MOLDING MACHINES 12 Sheets-Sheet 1 Filed Nov. 1, 1960 INVENTOR JOSEPH H. HOERN 2 M ffl/w ATTORNEYS May@25, 1965 J. H. HOERN DIE CASTING AND PRESSURE MOLDING MACHINES 12 Sheets-Sheet 2 Filed Nov. 1, 1960 INVENTOR JOSEPH H. HOERN 4' ATTORNEYS mS m:

May 25, 1965 J. H. HOERN DIE CASTING AND PRESSURE MOLDING MACHINES 12 Sheets-Sheet 3 Filed Nov. 1, 1960 IN VENTOR JOSEPH H. HOERN ts 10 I3 I 1 F IG. 3 B

6 ATTORNEYS y 25, 1955 I J. H. HOERN 3,184,810

DIE CASTING AND PRESSURE MOLDING MACHINES Filed Nov. 1, 1960 12 Sheets-Sheet 6 INVENTOR JOSEPH H. HOERN lw ww MW ATTORNEYS May 25, 1965 J. H. HOERN DIE CASTING AND PRESSURE MOLDING MACHINES 12 Sheets-Sheet 7 Filed Nov. 1, 1960 5 W m m n H H m m m M w w w. A M H X b 2 H w k m w E m M May 25, 1965 J. H. HOERN DIE CASTING AND PRESSURE MOLDING MACHINES 12 Sheets-Sheet 8 Filed Nov. 1, 1960 IIVVEIVTOR. JOSEPH H. HOERN ATTORNEYS y 25, 1965 J. H. HOERN I 3,184,810

DIE CASTING AND PRESSURE MOLDING MACHINES Filed Nov. 1, 1960 12 Sheets-Shet 9 FIG. l5

INVENTOR. JOSEPH H. HOERN ATTORNEYS May 25, 1965 J. H. HOERN 3,184,810

DIE CASTING AND PRESSURE MOLDING MACHINES Filed Nov. 1, 1960 12 Sheets-Sheet 10 FIG. I7

INVENTOR. JOSE PH H. HOERN gwagmgf w AT TOR NEYS May 25, 1965 J. H. HOERN 3,184,810

I DIE CASTiNG AND PRESSURE MOLDING MACHINES Filed Nov. 1, 1960 12 Sheets-Sheet 11 INVHVTOR. JOSEPH H. HOERN AT TORNEYS y 1965 J. H. HOERN 3,184,810

DIE CASTING AND PRESSURE MOLDING MACHINES Filed Nov. 1, 1960 12 Sheets-Shem. 12

Q m @915 9 MD) 3'23 1 INVENTOR.

JOSEPH H. HQERI?) ATTORNEYS United States Patent 3,134,810 DIE CASTING AND PRESSURE MOLDING MACHINES Joseph H. Hoern, 4161 El Monte, Saginaw, Mich; W. I. Yeo, executor of said Joseph H. Hoern, deceased Filed Nov. 1, 1960, Ser. No. 66,452 20 Claims. (Cl. 22-69) This application is a continuation in part of co-pending application Serial No. 852,554, filed November 12, 1959, now Patent No. 3,104,433, issued September 24, 1963.

This invention relates to machines for casting molten metal .or molding plasticizable material under pressure and more particularly to certain novel and useful improvements in machines of this type.

An object of the invention is to provide a material injection system of novel design wherein a shot plunger is moved first at a relatively slow speed which does not force material out of the pouring opening and thence at a relatively high speed which maintains a predetermined high pressure on the material fed into the die cavity, the system finally employing the shot plunger to push V out the biscuit as the dies are opening prior to the time the shot plunger is returned to its original position. Conventional die casting machines employ hydraulic mate rial injection systems which introduce a shock factor detrimental to the casting because there is a lack of constant pressure against the metal in the mold during the molding operation. These die casting machines employ pistons which also move at a relatively slow speed and spend their force in traveling the material into the mold cavity so that they maintain a relatively low pressure on the material in the mold cavity at the end of the stroke. The instant system is substantially mechanical in nature and obviates these difiiculties.

An important object of the invention is to design a die casting machine or the like as described having a mechanically driven shot injection system of practical and economical construction including a shot plunger which is moved with a high rate of acceleration from a stationary position to a shot injecting speed in the neighborhood of 800 feet per minute in the material injection stroke but can be retracted at a greatly decreased speed. The present machine avoids the rebound factor encountered with conventional hydraulic systems which permits detrimental expansion of the casting once it has been initially squeezed because the oil pump cannot keep pace with the piston.

Another object of the invention is to design a machine as characterized having a shot injection system of efiicient and reliable design in which a single drive motor operating to store energy for the acceleration mentioned also provides the necessary shot injection pressure and functions to retract the shot plunger. With such a system the control system required for automatic or semi-automatic operation of the machine is greatly simplified and the timed sequence of operation of many of the elements cannot be disturbed.

A further object of the invention is to design a rugged and durable machine requiring a minimum of maintenance and having a shot injecting system of the type described in which the motor to which reference is made attains full speed prior to the time it is required to provide the shot injection pressure.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings, in which:

FIGURE 1 is a side elevational view of the improved FIGURE 5 is a fragmentary, sectional, side elevational view taken on the line 55 of FIGURE 3 with the parts in the positions in which they are shown in FIGURE 4;

FIGURE 6 is a fragmentary, sectional plan view taken on the line 66 of FIGURE 3 with the parts similarly positioned;

FIGURE 7 is a fragmentary, transverse, sectional View taken on the line 7-7 of FIGURE 5;

FIGURE 8 is a fragmentary, sectional, side elevational view taken on the line 88 of FIGURE 7;

FIGURE 9 is a fragmentary, transverse, sectional view taken on the line 9-9 of FIGURE 5;

FIGURE 10 is a fragmentary, sectional, plan view taken on the line Iii-10 of FIGURE 9;

FIGURE 11 is a fragmentary, sectional, top plan view taken on the line III-11 of FIGURE 4;

FIGURE 12 is an enlarged, fragmentary, side elevational, sectional view with the elements shown in positions in which the traveling platen has moved to retracted position and the dies are open;

FIGURE 13 is an enlarged, fragmentary, side elevational view illustrating the right end of the machine shown in FIGURE 1 in more detail to show the mechanism for forcing the material to be cast into the dies, the mechanism being illustrated when it is in shot injecting position;

FIGURE 14 is an enlarged, sectional, side elevational view of certain elements of the shot injecting mechanism at a time when the shot injecting plunger is about to be moved rearwardly past the material introducing pouring spout;

FIGURE 15 is an enlarged, transverse, sectional view illustrating the manner in which the shot injecting elements are driven; I

FIGURE 16 is an enlarged, partly sectional, side elevational view taken on the line I6-16 of FIGURE 15 at a time when the shot engaging plunger is initially moving forwardly and the drive transmission elements are disengaged;

FIGURE 17 is an enlarged, transverse, taken on line 17-17 of FIGURE 16;

FIGURE 18 is a view similar to FIGURE 14 illustrating the manner in which the shot plunger is initially moved forwardly at a relatively slow speed past the pouring spout, the broken lines indicating the retracted position of the cam actuating plate on the shot plunger;

FIGURE 19 is a view similar to FIGURE 16 showing the parts during the terminal portion of the shot injecting cycle with the drive transmission elements engaged and exerting a supplementary drive force on the shot injecting plunger;

FIGURE 20 is a fragmentary view similar to FIGURE 16 illustrating the disengaged positions of the drive transmission elements just after the drive motor for moving the shot injecting plunger has been reversed just prior to the retraction of the shot injecting plunger.

FIGURE 21 is a view similar to FIGURE 16 showing the drive transmission elements engaged to retract the shot plunger;

FIGURE 22 is a schematic view illustrating a typical electrical control system for the machine;

FIGURE 23 is an enlarged fragmentary, sectional side sectional view elevational view illustrating the friction clutch which is mounted on the rack driven shaft; and

FIGURE 24 is a fragmentary, sectional, side elevational view illustrating a modification in the final die closing mechanism.

Referring now more particularly to the accompanying drawings, in which only a preferred embodiment of the invention is. disclosed, a letter F generally indicates the frame of the machine which is particularly designed to avoid the use of a heavy and bulky bed or base of the type which previous die casting machines have employed. Support block members It are spaced longitudinally and transversely, as shown in FIGURES 1 and 3, to function as corner posts and are arranged to support a rear end plate 11 and a front end plate 12. Bolts 13 (FIGURE 3) may be employed to secure the end plates 11 and 12 in position on the corner blocks and side plate members 14, which are recessed as at 15 to receive the end plate members 11 and 12, can be suitably secured to the end plate members by bolts 16. The support blocks it), end members 11 and 12, and side plate members 14 which may be perforated as at Ma and 14b to provide access to the interior, comprise a rigid, stationary frame section for supporting a die casting machine which is designed to exert a pressure in the neighborhood of 800 tons.

Mounted on the rear plate 11 by bolts 17 and spaced from the plate 11 by spacer sleeves 18 is a stationary, rear support plate 19 designed to cooperate with the plate 11 insupporting final or die closing pressure applying means in a manner which will be later described. The plate 19 also supports drive elements for operating the final or closing pressure elements and for rapid traversingthe movable die platen 20 forwardly and rearwardly to and from a position in which the movable die member 21 thereon is in a forward position adjacent the stationary die member 22. As has been previously noted, the instant die casting machine avoids the use of an elongate hydraulic cylinder for moving the traveling platen 28 to and from the position in which the final closing pressure is applied. Instead, a mechanical rapid traversing arrangement is employed in conjunction with die closing pressure exerting members which obviates many of the difficulties encountered with so-called hydraulic machines.

The rapid traversing mechanism Mounted on the plate 19 (see FIGURE 5) is a tapered around a pulley on the armature shaft'36 of a motor 37.

Tubular shaft or sleeve 29 extends through an opening 38 in the plate 19 and through an opening 39 in the plate 11 and a roller bearing 40 is provided, as shown, to support the front end of the shaft 29. Bearing 40 comprises an outer race member 41, roller bearings 42, and an inner race member 43 secured in position by a head plate or bearing cap 44 with bolts 45 or in any suitable .having a section fitting into a central opening 52 in the travelingplaten 2t Bolts 53 secure the plate 51 and a flanged end member 54. The end of the screw 49 is provided with a pair of opposed, horizontally extending notches or grooves 55 which receive the flanges 56, provided on the plate 53. The flanges 56, prevent axial rotation of the screw 4-9, however, it will be seen that they are of lesser thickness axially than thewidth of grooves 55, so that the traveling platen 2% can have a slight relative axial movement in the member. 59. This clearance Sea, which may amount to 7 3 of an inch, will permit the traveling platen, 20 to move forwardly the required distance when the closing pressure is applied.

The die closing mechanism Extending rearwardly from the traveling platen 20, and rigidly fixed thereto, are radially disposed, thrust rod members 57 which are arranged radially equidistant from the central screw 49 on the platen2tl in uniformly spaced, circumferential relation, so that a relatively uniform closing pressure may be applied. The final closing force of 890 tons is applied to the thrust rods57, which are secured to the traveling platen 2t) by bolts 58 (FIGURE 4) through similarly arranged piston assemblies generally designated 59 supported by the plates 11 and 1% in axial alignment with the thrust rods 57 (see FIGURE 4). The piston assemblies 59, which are received in cylinders 6t) secured to the plate 19 by screws 61 include heads 62, return spring retainer plates 63, "and sleeve members 64, which are threaded assat 65 to adjustably receive the cooperatively threaded, pressure applying sleeve members 66. The piston head members 62 are open as at 62a so that the position of the members 66, which have enlarged heads, as shown, may be axially adjusted to suit the particular dies being used so that the stroke of the piston units 59 is varied but very slightly. Further,members 66 are bored as at 66a so that they can receive thrust rods 57 (see FIGURE 12) during the retraction stroke of the platen 26 when blocking members 67 are moved from between the sleeves 66 and shafts 57, as shown in FIG- URE 12. The blocks 57 are automatically" positioned between the members 65 and shafts 57, just prior to applying the closing pressure, and are raised prior to the retract stroke of the traveling platen 2t) so that the thrust rods 57 may enter, the sleeve 66 in a manner which will be presently described. The adjustment of sleeves 66 is accomplished through a chain 68, as shown in FIGURES 4 and 7, which is trained around sprocket members 69 fixed on the sleeve members 64. The sleeves 64 at their opposite ends have flanged portions 64a, received between the rear face of the piston head members 52, and an internal shoulder 7% formed in each spring retainer member as so that the members are substantially axially restrained and rotation of members '64 will adjust the members 66 axially.

As shown in FIGURES 7 and 8, adjustmentof the members 66 can be a manual operation, the plate 11 having mounted thereon a sprocket member 71 having a hexagonal head portion '72, which may be gripped by a wrench. A threaded pin 73'canbe provided. to secure the sprocket 71 on the plate 11 and access to the sprocket 71 may be had through one of the openings 14a in the side plates 14.

Provided inthe circumferentially spaced openings 74 in the members 63 are springs 75, which return the piston assemblies 59 when the closing pressure is released. It will be seen that the spaces necessary for die closing travel are provided between the shoulder on each piston head 62 and stop plates 78 which are bolted to the cylinder members 60, as at 79. It is important to note that the piston assemblies 59 do not reciprocate with the traveling platen 20, but rather are, in etfect, a portion of the frame. The plate 19, in fact, forms the head of each cylinder and each has an axially directed passage portion 8% leading to the interior 81 of the, cylinder, as shown in FIGURE 4. The piston assemblies 59 are moved forwardly inja manner which will be presently described, only when the ball screw 4-9 has rapid traversed the traveling platen 2b forwardly to a position in which the, dies 21 and 22 are substantially adjacent or contiguous.

Supported from the frame plates 19 and 11 is a motor support plate 82, which supports not only motor 37 but a motor 83 as well. Sleeve members 84 fixed by bolts 85 extending into the top of plate 11 may be provided on the plate 11, as shown in FIGURES 1 and 3, to assist in supporting the plate 82. The motor 83 is connected to drive a shaft 86 through the medium of a belt 87 trained around a pulley 88 on the armature shaft 39 of motor 83 and a pulley 90 keyed on shaft 86. As shown in FIGURE 4, the shaft 86 to which pulley 90 is keyed is tubular and is rotatably supported on a stub shaft 91, which carries roller bearings 92 and 93. Roller bearings 92 and 93 comprise inner race members 92a and 93a,

outer race members 9212 and 93b, and balls 92c and 930, respectively. This stub shaft 91 has an inner end 91:: received within a bore 94 provided for it in the frame wall 19. Spur gear teeth 95 are provided on the shaft 86 and, as shown in FIGURE 6, are in meshed driving relationship with a pair of gears 96 and 97 which are fixed on ball screw shafts 98 and 99, respectively.

Bearing support members 100, fixed in openings 101 provided for them in the wall 19, support tapered roller bearings generally designated 102 within which gear hub portions 96a and 97a are rotatably received and roller bearings 193 are provided to revolvably support the outer ends of ball shafts 98 and 99. Roller bearing 1133 comprises inner race members 103a, outer race members 183b, and balls 1030. The tapered roller bearings 102 include outer race members 104, rollers 105, and inner race members 1%. The bearing support members 100 are secured to the wall 19 by bolts or screws 1137. Gears 96 and 97 are keyed to their respective shafts 98 and 99 as at 103 and the ends of shafts 98 and 99 are threaded as at 169, so that nuts 11% may be employed to secure the gears 96 and 97 in position on the shafts 98 and 99, respectively.

Traveling ball nut assemblies of conventional design generally designated 111 are provided on the screw shafts 98 and 99 and support a yoke or actuator plate 112 which applies the die closing pressure in a manner now to be described. The assemblies 111 comprise nut members 113 with recirculating balls 114 and are secured to the plate 112 by screws 115. Yoke member 12 has openings 117 for freely passing the screw shafts 98 and 99 and since the front ends of shafts 98 and 99 are received in thrust bearings 18 provided in a plate 119 which is fixed on the frame F, it will be plain that, upon rotation of the axially fixed screw shafts 98 and 99, the nut members 113 and yoke 112 will move axially.

FIGURES 4 and 6 show the cylinder 120 which is fixed to the wall 19 by a shouldered plate 121, in any suitable manner, as by using bolts or screws 122. The reciprocable connecting plate 112 mounts a guide sleeve 123 having an end wall 124 by suitable screws or bolts 125 and, as will be noted, the sleeve 123 telescopically receives the cylinder 120. Cylinder 129 houses a piston assembly 126 which dispenses fluid under pressure to the cylinders 60 from the fluid supply chamber 127 closed by the piston assembly 126 to apply the closing pressure of some 800 tons. A passage 128 communicates with the cylinders 69 through a transversely disposed passage 129, vertically inclined passages 136) (FIGURE 3), vertical passages 131, and the passages 80.

The mechanical advantage obtained through use of the relatively small piston 126 which displaces the considerably larger diameter pistons 59 is an important factor since it is desired that the pressure exerted by each of the piston assemblies 59 be in the neighborhood of 200 tons. The communicating passage system provided solely in plate 19 and leading from the chamber 127 will always be completely filled with the incompressible fluid used, which suitably may be a liquid silicone. It is desirable that the fluid used be incompressible, non-inflammable, and nonabrasive in character.

The piston assembly 127 is bored, as at 132, to receive a guide pin 133 having semispherical ends 134 and 135, as shown. The conical end walls 136 and 137 which receive the ends 134 and 135, respectively, are formed in the piston 12%, as shown, and in the cross head or connecting plate 112 which receives the other end of guide pin 133, and with this construction misalignment of the parts is effectively prevented. The guide pin 135 has a flange 133a received within an enlarged portion 132a of the bore 132, a ring 138 being provided fixed to the piston 126 to maintain this connection of the guide pin 135 and piston 126. It will be noted that the diameter of the flange 133a is less than the internal diameter of the enlarged portion 132a of the piston, so that some tilting of pin 135 can occur without binding.

Plainly, when the piston 126 is moved toward Wall 19 by the cross head 112, a closing pressure is applied to the piston assemblies 59 and conversely when the piston 126 is moved outwardly in the cylinder the springs 75 return the pistons assemblies 59 and piston 126 to original position.

As has been noted, the traveling platen 20 carries the movable die member 21. Both motors 37 and 83, through the intermediary mechanism which has been described, operate to control the movement of the platen 29. The motor 37 operating through the screw shaft 49 moves the platen 20 from a distance considerably removed from the fixed die 22 to a position in which dies 21 and 22 are substantially abutting and the motor 83, thence, through piston assemblies 59 applies the considerable closing pressure which moves the die 21 the very short additional distance into clamped engagement with the fixed die 22. No tie rods are necessary in the instant machine since it is not necessary to distort the frame to allow for any misalignment of the dies 21 and 22. Rather, the 800 ton force which is necessary, not to move the dies 21 and 22 into engagement but to retain them in sealed engagement when the die cast metal is injected into the die cavity, is applied at uniformly spaced apart areas of the platen 20.

As shown in FIGURES 2 and 3, particularly, the platen 20 is supported for reciprocating travel by the frame side plates 14 to which T-shaped guides 139 are fixed by suitable screws or bolts 1411. Rail members 141 secured on the T-shaped guides 139, as with screws or bolts 142, cooperate with the members 139 to define channel-shaped guides 143 which receive the slide members 144 which are fixed to the upper end of the traveling platen 2t) by bolt members 145. The plate 119, which cooperates With plate 19 to support the screw shafts 98 and 99, is fixed to block members 146 which are bolted, as at 147, to the top rail members 141. The arrangement described wherein the guides or ways are, in effect, provided in the side walls of the frame to support the traveling platen 20 in its reciprocation toward and away from the fixed die member 22, provides a construction which is believed greatly superior to die casting machines of conventional construction employing tie rods on which the traveling platen slides.

It has previously been mentioned that, when the traveling platen 20 is in rearward or outward position, the thrust rods or shafts 57 are received within the piston members 66. When the traveling platen 2% is moved forwardly by the screw shaft 49 to a position in which die 21 is about of an inch from die 22 the piston members 65 and thrust rods 57 will be spaced from one another a predetermined distance. In order that pressure may be exerted on the thrust rods 57 by the piston members 66, the block members 6'7 are moved from a position outward of the bores 66a in members 66, as shown in FIGURE 12, to a position sandwiched between the members 66 and 57, as shown in FIGURE 4. This movement of the blocks 67 occurs in a manner which will now be explained when the platen 26 has been moved forwardly by the screw 49 and the thrust rods 57 are sufficiently forwardly to permit entrance of the blocks 67 between the rods 57 and mem- 7' V bers 66. A plate 148 mounting the ejector rods 149 which extend through passages 156 in the platent 26 and 151 in the die member 21 is provided between the side frame members or plates 14 between the fixed end plate member or abutment wall 11 and the reciprocating platen 20, as shown in FIGURES 4, 5, and 9. The front ends of piston members 66, which are of enlarged diameter as shown in FIGURE 10, are formed with vertically disposed grooves or passages 152 therein, for admitting the blocks 67. Each member 66 has a pair of side flanges 66b against which clamping members 153 bear to secure the piston member 66 to the plate 148, suitable screws or bolts 154connecting the members 153 and plate 148 and thereby the piston members 66 and plate 148 for. longitudinal movement, as shown. The plates 67 are of such thickness, relative to the length of the portions 152, as to provide the necessary clearance for movement of blocks 67.

Plate 148 has an opening 156freely passing the nut member 47 and openings 157 which freely pass the thrust rods 57. The blocks 67 are connected at each side by vertically extending, rigid straps 153, as shown in FIG- URES 9 and 10, the straps 158 being suitably secured to the blocks 67 by rivets or the like 159. The straps 158 at the right side of plate 148 in FIGURE 9 extend above the upper block member 67 and are connected by a bar 160, asshown. Lugs 161 provided on the bar 166 and on the. top of the uppermost block 67 at the left side of plate 148 .in FIGURE 9 connect to link members 162 which suspend the system from an actuator member 163 which is automatically operated upon movement of the yoke 112 to operate piston assemblies 59 in a manner which will be later, described. The links 162 are pivotally con-' nected to the lugs 161 and extending arms 163a of the actuator 163 by pins 164, as shown. As indicated in FIGURES and 9, the actuator member 163 is pivotally mounted on plate 148 as at 164- and has a spherical shaped, upper end 165 received, as shown, within a clevis 166 (FIGURES 9 and 11) on the one end of a rod member 167. In FIGURE 9 the actuator 163 is disposed such that blocks 67 are in alignment with thrust rods 57 in a position to permit the piston members 66 to apply pressure to the rods 57. If the actuator member 163 is oppositely tilted, however, about its pivot 164, the left hand blocks 67 (FIGURE 9) will'be raised to the position in which they are shown in FIGURE 12, out of the path of thrust rods 57 and the right hand blocks 67 will be lowered the same distance so that they also are out of the path of thrust rods 57. Retracting movement of the yoke .112, which adjusts the position of the actuator 163 to move the blocks 67 out of the path of the thrust rods 57, will free the bores 66a of piston members 66 for entry of the rods 57 on the retraction stroke of platen 26. j

The mechanism for automatically operating the actuator 163 will be next described, and attention is directed particularly to FIGURES 4, 9, and 11 for a disclosure thereof. The fixed wall 19 mounts a fixed clevis 168 under cylinder 126 and a clevis pin 169 supports a sleeve 176 for swinging movement in a horizontal plane. Fixed on the member 176 which is provided with a front bearing 170a is a cam or track member generally designated 171 and having a trackway 172. with an angularly directed portion 172a. Front and rear clamp members 173 are employed to fix the track member 171 in position on the tube 170. Mounted on the underside of cross head or connecting yoke member 112 by bolts or screws 174 is a plate 175 carrying a dependent roller 176 which rides in,

the cam track 172. The tubular member 17 it telescopically receives the rod 167 and when the roller 176 reaches the portion 172a of the track 172 it will necessarily'pivot the sleeve 176 and rod 167 about the pin 169. This, of course, has the effect of changing the position of the actuator 163 about its central pivot point 164. The plate 177, which is mounted on the upper edge of the plate 148 by screws178 or the like, supports the outer end of the 8 rod 167 and is slotted as at 179 to permit free movement of the upper endof the actuator member 163'. If the position of piston members 66 is adjusted axially relative to 7 member 64, as in a case where a die 21 or 22 havinga different thickness is being substituted for the die in the machine, the rod 167 is free to move axially in the tube receive T nuts 181 which are threaded onscrews 182- carried by the die members; In the case of the die 21, the die face is provided with enlarged openings 133 at points peripherally spaced from the die cavity 184 to receive the heads 185 of screws 182.. The T slots which are not used in the drawings may be employed with other dies providing that the openings 182a leading through the die members 21 andZZ are outside and spaced from the die cavity 184. I As previously. noted, the ejector rods 149 are carried by plate 148 and extendsv through to a position in which they are flush with the surface of the die cavity 184. During the retract stroke of platen 20 when the piston members 66 are moved rearwardly initially by the piston return springs 75, the ejector pins 149 will move the slight distance rearwardly with them.: However, /hen the platen 26 is rapid traversed rearwardly by the screw shaft 49 the pins 149 will operate to strip the casting from the mold cavity so that it is free to fall to a suitable conveyor or the like positioned under the machine. Since the machine is supported on blocks 10 at its corners only, ample space is provided so that an endless conveyor may extend under the machine to convey the castings which are formed in the machine on a quantity productionschedule- When the position of piston members66 'is being adjusted and the screws 154 holding clamp plate 153 are backed off slightly to permit rotation of the piston members 66, the pins 186 projecting outwardly from plate 148 assist in supporting the plate 143 in position.

The shot injection system The charge of metal is applied to the die cavity.184 in a novel manner which will now be disclosed, the shot injection system being illustrated particularly in drawings l, 2, and 13-21. Preferably, as previously noted, a shot injection plunger 187 is employed which moves at a relatively slow rate of speed initially to close off a material supply spout, thence at a great rate of speed, and with tremendous force, to move the molten metal or the like into the die cavity 184, and finally at a relatively reduced rate of speed while retracting to original position. A longitudinally disposed, rectilinear housing 188 supported at one end by the Wall 12 and at the other end by an upright housing or casing 189 is provided to house the shot plunger 187 which has an enlarged end 187a and is adapted ,to extend through an opening or cold chamber 190 in fixed die 22 .and an aligned opening or cold chamber 191 throughwall'12. The housing 188, which includes side walls 192 and partial top wall 193, has integral side flanges 194 so that itcan be secured to the end wall 12 by bolt members 195.

It will be seen that the passages 190 and 191 are of the diameter of the enlarged head 187a oftheinjection rod or plunger 187 and mountedon the rear wall 12 is a member 196 having a bore 197 of the same diameter as openings 199 I and 191. A pouring spout 1% leads through the member 1% from the exterior thereof to' ceived within a horizontally disposed rack 2%. The upright housing, generally designated 189, includes side walls 202, and top and bottom walls 2113 and 2 .14, respectively, and horizontally aligned support rollers 2115, on rods 2115a spanning the side walls 2112, support the rack member 2191 for reciprocation longitudinally. The outermost end of slide 19": extends into a chamber 2% provided in a piston 2117 which is housed in a cylinder 2113 carried by the rack 201. An air supply conduit 2419 communicates with the interior of the cylinder 208, as does an electro-pneumatic pressure switch 210. The cylinder 298 is connected to the rack 201 for movement therewith by a dependent arm 211 having a roller 212 thereon for supporting the rear end of the rack from a platform 213. Braces 214 support the platform 213, which has front support wall 215 and stop 216 at its opposite ends. The cylinder 208 and accordingly slide 195 are carried along with the rack 2111 in its froward shot-injecting movement and afterward, when the casting has cooled and it is desired to eject the biscuit from the portion 1913a (see FIGURE 1) of passage 190 in front of the head 187a of the shot plunger when it is in innermost position, thepiston 207 is moved by the pressure of air in cylinder 2&8 in a manner to be de scribed to move the slide 199 and shot plunger 187 inwardly, independently of the rack 29!. It is desirable that the shot plunger 187, when in retracted position outwardly of the pouring spout 193, be moved relatively slowly until it clears or is inward of the lower portion of pouring spout 193, and to this end a reversible electric motor 218 is provided, supported on a motor plate 219 fixed on housing 189. The armature shaft 22%) of the motor has a semi-annular cam 221 fixed thereon which has spaced apart, shot plunger actuating end surfaces 222 and 223. The motor 218, which is used only for opening and closing the pouring port, may be simply a conventional /1 HP. reversible motor which is started and stopped to move the cam 221 through a part of a revolution. Plate 224, carried by the coupling assembly 2%, depends into the path of the cam 221 and will be actuated thereby to move the head of the shot plunger 13'? inwardly past or outwardly to clear the pouring spout 1% when the plate 224 is adjacent to either of the surfaces 222 or 223. In FIGURE 18 the depending plate 224 is shown immediately after it has moved plate 224 and shot injector 187 from their outermost position, which is indicated by the broken lines in the drawing, to a position in which the head 187a of the shot plunger 187 has just passed the pouring spout 1%.

Once the shot plunger 187 is moved past the pouring port 198, it is desirable that it move the metal into the mold cavity 184 at a very rapid rate of speed and with tremendous force. In the instant case, this force or energy is supplied by a blast-off air cylinder 225 which releases stored energy to drive the rack 2tl1, and thus slide 199 and plunger 187, inwardly with a very high rate of acceleration which quickly brings the plunger 187 to a speed in the neighborhood of 800 feet per minute. The cylinder 225, which extends through the top wall 2173 of housing 189 and is supported thereby, is open at its lower end, as shown, to permit a vertically disposed rack 226 to enter the cylinder 225. A free piston 227, mounted for reciprocation in the air cylinder 225, is moved upwardly in the cylinder 225 to compress the air or other fluid therein initially and store energy in the cylinder 25, so to speak, and later to move the rack 226 downwardly when the stored energy is released. Rack 226 is in mesh with a pinion 228 (see FIGURES l3 and 15) on a shaft 229 journaled in bushings 239 in the side walls 202 of housings 189 and, as illustrated in FIGURE 15, the pinion 228 is of suificient length so that its teeth are in mesh with and drive the teeth of rack 2111. The vertically disposed rack 226 is supported by the right hand lower roller 285 in FIGURE 13 and a similar upper roller 2115b mounted as previously on a pin 2115a spanning the walls 202.

Once the energy stored in cylinder 225 has moved the shot plunger 137 to force the material into the mold cavity 134, it is desirable that the shot plunger 137 be held in position with great force during the time that the metal is solidifying. Since much of the energy stored in cylinder 225 is dissipated, it is desirable to provide an auxiliary drive for exerting the holding force for the shot plunger. This drive is also employed for returning the shot plunger 187 to retracted position, during which time energy is stored in cylinder 225. It is desirable that the single motor, 231, which is capable of accomplishing these functions, be brought up to speed before the loads contemplated are placed on the motor, and the drive transmitting mechanism which permits attainment of these objectives will now be described. The drive can be furnished by the single, reversible electric motor 231 in a manner presently to be explained. The motor 231 is a conventional, 30 H.P., 1800 r.p.m., reversible electric motor with an 8l3% slip factor (Louis-Allis type, Cog K NEMA Design D, 3 phase, 60 cycle). Motor 231 has a sprocket 233 mounted on its armature shaft 234 which drives a sprocket 235 mounted on a shaft 236 carried in bearings 237 by the side walls 202 of housing 189 through the medium of a chain 238. Keyed on the opposite end of shaft 236 is an elongated pinion gear 239 in mesh with gear teeth 240 provided on a drive transmitting member 241. As shown in FIGURE 17, the gear teeth 24113 are provided on the peripheral face of the member 241 which is journaled for rotation on a bearing generally designated 242 mounted on a shaft generally designated 243 and supported between shafts 236 and 229 in bearings 244 carried by the side walls 292, as before. Shaft 243 has a gear 245 fixed thereon which is in mesh with a gear 246 keyed on the shaft 229. Flywheel 246a is fast on the gear 246. The drive imparted to gear 240 is transmitted to shaft 243 only at certain times during the reciprocatory cycle of the shot plunger 187, motor 231 being started in advance during the cycle to enable it to attain speed prior to loading it.

Bearing 242 comprises an outer race 247, roller members 243, and an inner race member 249. A flange 2511 is provided on the shaft 243 to receive the inner race 249 of the bearing and the shaft 243 is grooved as at 251 so that it may receive a spacer ring 252 which maintains the bearing in axial position. The outer face of annular member 241 is provided with an annular recess 253 which receives a pair of spaced apart members 254 and 255. The recess 253 is shouldered as at 253a to provide a peripheral seat for the member 254 and it will be seen that member 255 is received on a reduced portion 256 of shaft 243 and is rigidly secured by means of bolts 257 to an annular flange 253 provided integrally on the shaft 243. Member 254 is fixed in member 241 so that there is no relative rotation of these members. The outer ring 254 is peripherally spaced from the inner ring member 2'5 as at 260', and received in alternate relation in the space 2611 are pins or rollers 261 and axially projecting tine or finger members 262 carried by an annular spider member generally designated 263 which is bolted as at 253a to a gear 264 mounted on a reduced portion 265 of shaft 243. The gear 264 is fixed by bolts 266 to the magnetizable iron wear ring 267 of an electric clutch (FIGURE 17) generally designated 26% which also includes the usual electric coil-wrapped core member 269 fixed to a plate 271 secured as by screws 271 to a bracket 272 on housing wall 202. When current energizes the clutch 263, the ring 267 is magnetized by the core element 269 which has lead wires 269a. The opposite iron wear plate 267a is drawn to wear ring 267 and the result is to couple it magnetically to plate 267, when core 269 is energized. The air space x between core 269 and plate 267 prevents the core 269 from interfering with rotation of plate 267. When the clutch 268 is deenergized, plate 267a rotates freely relative to plate 267. A roller bearing generally designated 273 and having an 11' inner race 273a, outer race 273b, and roller bearings 273a rotatably mounts a gear 274% in mesh with pinion 239'. The end plate 267a of clutch element 267 mounts on the hub of gear 274 and it will be seen that pins 275 mounted by the gear. 274 extend into openings 276 in the. clutch element 267a and fix the gear 274 and element 267a rotatively. A bolt 277 and washer 277a retain the bearing 273 and other parts. Theclutch 268 may be the conventional SFseries clutch manufactured by Warner Electric Brake and Clutch Company of Beloit, Wisconsin. It is important to observe that while the inner peripheral surface. of ring 254- is annular, the adjacent peripheral surface of member 255 is polygonal and formed with-a plurality of flatted faces 278. Each of the fiatted surfaces 273 is of a length slightly greater than the sum of the diameter of one of the rollers 26]. and the circumferential width of one of the actuator tines 262. Further,

the radial space between members 254 and 255 is such that when a roller 261 is generally centrally disposed with respect to a surface 273, the clearance a is greater than the diameter of rollers 261 so that there can be relative rotation of members 254 and 255 without interference. Howevenif the rollers 261 are moved to the end positions with respect to surfaces 278, the rollers 261 will be wedged in driving relationship between the members 254 and 255. This-occurs, of course, because the distance b is less than the distance a and less than the diameter of rollers 261. In FIGURE 19 the cylindrical rollers 261 are shown wedged inposition at a point where the clear ance b is lessthan the diameter of pins 261 so that elements 254- and 255 are in driving relationship.

The relative rotation of actuator member 263 and the driven element 255 which is fixed to shaft 243 is affected by gear 264 which, in addition to being fixed to the elec-v tric clutch element 267, is in mesh with a gear 279 mounted by a friction clutch generally designated 280 which is provided on shaft 229. Clutch 280 (FIGURE includes an outer member 281a and an inner member 28113 (FIGURE 23), each mounting a Wear ring 282 which engages gear 279. Bolts 283 seated in openings 2810 provided through the outer member 281a and threaded into openings 281d in the inner member 281b cooperate with coil springs 284 in a state of compression to hold the Wear plates 282 in engagement with gear 27 9 with sufiicient pressure so that it normally drives'gear 264 but can slip when requiredto do so. Members 281a and 281b are,;of course, fixed on shaft 229 for rotation therewith. The drive ratios of the sets of gears 279, 264 and 245, 246V differ, gear 264 being driven at a slightly greater rate of speed by gear 279 than gear 245 is driven by gear 246 when rack 226 is forced downwardly, as will later become clear.

The control system and operation At the beginning of thecycle when platen 20 and retractable die 21 are in rearward or retracted position and rack 201 and slide 199 are also in retracted position (see FIGURE 14), the operator, in putting the system into operation, first of all must start the rapid traverse motor 37 and this can be done by depressing a push button 285 (FIGURE 22) to start the operation of the control system. The control system which will be described may be varied considerably so that the operation of the machine is entirely automatic or may be made somewhat semiautomatic so that the, machine is at least partially under the control of an operator. The instant system which employs timing cams is shown for the sake of simplicity of illustration and pictures the system as ready to begin a cycle of operation. When button 285 is depressed to energize conduit 0, the geared down timer motor 286 is started and continuous to revolve its timer cams in the usual manner through a complete revolution during which time one cycle of the machine is completed. The cams may be mounted on an extension of the motor shaft adjacent the switches they are to operate, in the usual manner. When timer 2% is started, cam 287 moves counterclockwisely, as do all the timer cams, to close normally open'switch 288 in circuit d and motor 37 is energized to revolve shaft 29. Nut 47, through shaft 49, moves platen 2t forwardly and when movable die 21 is approximately of an inch from stationary die 22 the cam 287 permits switch 233m open. At the same time, cam 289 closes normally open switch .290 in circuit line ,f and circuit line f is closed to, start motor 83. Energization of motor 83, as has been noted, revolves screw shafts 98 and 99 through pulley tls, shaft 86, and gears. 95,96, and 97, and since shafts 98 and 99 are fixed in position axially, nuts 133 move the yoke 112 toward the wall 19 to the left, as shown in FIGURE 6, which forces fluid under pressure through-the passage system 128, 129, 132, and 131 to the ports 82 entering cylindersdti.

During the time that piston 126 is moving toward the left (FIGURE 4) in cylinder 12%, the arm carrying roller 176, which is secured to yoke plate 112, is moving toward the left in the track 172. The thrust rods 57, having been moved forwardly by the screw 49, are clear of the bores 66a in the piston member 66 sufliciently to permit the introduction of plates 67. Atthe outset of the closing movement of piston .126 and yoke 112, the roller 176 is in the portion 172:: of the trackway 172 and trackway 171, sleeve 170, and clevis rod 167 will accordingly almost initially be pivoted about pin 169 to pivot actuator plate 163 about pivot 16 to the position shown in FIG- URE 9 and move blocks 67 vertically into place between the piston member 66 and thrust rods 57. Accordingly, as the piston assemblies 59 are forced forwardly and move the die 21 into engagement with the fixed die 22, the force of 800 tons is exerted on the platen 20 through piston members 66, blocks 67, and the thrust rods 57. V

The timer cam 2% holds the dies 21 and 22 in closed position for a predetermined period of time, after which it permits switch 2% to open again. After the material has been injected into the die cavity in a manner to be described and the part formed has had suificient time to cool, the reversing circuit g ofmotor 83 will beenergized to drive motor 83 in a reverse direction and move piston 126 outwardly so that springs 75 will return piston assemblies 59. This is accomplished by the cam 291 closing normally open switch 292 atthe time switch 296 is permitted to open. When piston assemblies 59 have returned to retracted position,.normally open switch 293 in the reversing circuit e of'motor 37 is energized by cam 294 which closes normally open switch 295, and motor 37 is driven reversely to retract screw 49 and platen 26 to out position once again.

During the retracting movement of piston 126 the arm 175 and roller 176 are moved in the same direction and clevis rod 167 is returned to pivot acuator plate 163 about pivot 164 and move the blocks 67 vertically out of sandwiched position between piston'members 66 and thrust rods 57. Accordingly, when motor 37 is driven in the reverse direction to retract the platen 20, the thrust rods 57 will be received within the bores 66a of members 66 in the manner demonstrated in FIGURE 12. As the platen 25B and movable die 21 retract, the ejector rods 149 will, of course, operate to separate the casting from the die cavity 184.

When the platen 2t) and die 21 are in fully retracted position prior to commencement ofthe operation as described, the shot injecting plunger 187 is also inretracted position with its head 187a outwardly of the pouring spout 193, and cam 221 is in the position in which it is shown in diagrammatic lines in FIGURE 14 just after it has moved the slide 199 and plunger 187 outwardly relative to rack 261 and cylinder 208. The motor- 231 is off and the conventional electric brake 284 shown in circuit line It is energized or applied so that shaft 243 in FIGURE 15 is locked in position. First of all, when. the platen 2t) and shot plunger 187 are in retracted position, molten metal or the like is poured in a measured amount into the pouring spout 108, the quantity of material used being that suflicient to fill the die ca ity 184 and provide a minimum biscuit in passage portion 187a. It will be seen that clutch (268) timing cam 2%, at the time of the depression of button 285, does not close normally open switch 297 in circuit line i so that at the outset clutch 268 is disengaged, element 207 being free of element 267a when the clutch is in a deenergized state. The friction discs 282 through gear 279 hold spider 263 in the position in which it is shown in FIGURE 16. Almost at once, timer cam 20% closes normally open switch 299 in circuit k to start motor 231 and drive it in a direction to move the shot injection plunger or ram 187 inwardly if motor 231 were connected to drive member 187. With motor 231 driving member 254 counterclockwisely in a direction reversed from its previous direction of rotation, the rollers 261 are, as shown in FIGURE 16, moved counterclockwisely from the position in which they appear at the end of a cycle (see FIGURE 21) out of wedged engagement between surfaces 254 and 255 to a neutral, central position so that motor 231 is not at this time connected to ram 187. The drive member 241 simply spins freely while motor 231 attains its rated speed. When the rollers are clockwisely wedged as in FIGURE 21, rotation of drive member 241 counterclockwisely forces roller 261 to neutral position (spider fingers 262 moving with them because clutch 280 slips) but, of course, cannot force them beyond neutral position. Movement of the ring 254 in a direction opposite to the direction in which the rollers 261 were wedged into place always dislodges the rollers because the wedged relationship cannot exist where the one wedging surface moves away from the other in a direction counter to the direction of wedge.

At substantially the same time motor 231 is energized, timer cam 300 closes normally open switch 301 in circuit line m to energize motor 218 and drive it in a position to revolve cam 221 counterclockwisely. The cam end surface 222 engages plate 224 to move plunger 187 forwardly at a slow speed in the neighborhood of 25 feet per minute until the head portion 187a of the plunger has closed off pouring spot 1%. Just before motor 218 is deenergized by cam 300 permitting switch 301 to open, plate 304 on cam 221 trips and opens normally closed switch 305 in the brake circuit line It and the piston 227 is free to force the rack 201 and consequently ram 187 inwardly with the tremendous force of the some 50,000 pounds of energy stored in cylinder 225. The speed of travel of the ram can be varied somewhat by changing the compression space in the cylinder 225 or by varying the weight of flywheel 246a. When brake 284 is released and rack 201 is being, in a sense, blasted inwardly so that shaft 243 almost immediately overtakes gear 240, the rollers 261 remain in the position in which they are shown in FIGURE 16. This is the case because, although spider 2&3 is rotating at a slightly greater speed than shaft 243 due to the difference in gear ratios mentioned, the speed of member 254 is less than the speed of inner member 255 and this factor prevents the rollers 261 from moving into positive wedge engagement. Thus members 241 and 255 remain uncoupled while the clutch 280 slips. As the stored energy in cylinder 225 is being expended, the speed of member 255 and spider 263 drops toward the end of the stroke of ram 187 below the speed of gear 241 which brings the rollers 261 into the wedged engagement in which they are shown in FIGURE 19. Once the rollers 261 are wedged the clutch 280 slips to compensate for the difference in gear drive ratios mentioned. Thus, when the energy in cylinder 225 is expended to the extent that member 254 catches and commences to overrun member 255, when the shot plunger is substantially at its innermost position and meeting substantial resistance, the rollers 261 are wedged counterclockwisely between the 14 members 254 and 255 and the drive of motor 231 is imparted to shaft 243 and rack 201 through gear 24-5, 246, and 228. FIGURE 19 shows the elements in this position in which motor 231 is applying a predetermined pressure on ram 137. When the piston 227 is moving rack 201 inwardly up to the final increment of stroke when substantial resistance is met, the normal pressure of p.s.i. is maintained in cylinder 208 and the piston 207 is spaced somewhat more from the outer end of cylinder 208 than shown in FIGURE 13. At the time when ram 187 and slide 199 are substantially stopped, rack 201 and cylinder 208 continue to be driven forwardly by motor 231 as described and the air in cylinder 208 is compressed as indicated in FIGURE 13. Approximately 50,000 pounds of holding pressure can be very conveniently developed in this way. When conventional spring returned pressure switch 210 is activated by the pressure in cylinder 208 reaching a predetermined value, its normally closed contacts 210a and normally open contacts 21011 in circuit lines k and k1 are respectively opened and closed and motor 231 is stopped and brake 28d energized. Accordingly, the force of 50,000 pounds continues to be exerted on the ram 187 and is operative to force out the biscuit portion of the part or casting in portion 190a of the shot injecting passage when the die 21 is retracted and the part is ejected. Once the shot is completed, and While waiting for the casting to cool, drive motor 231 is energized to move member 254 in a reverse direction when timer cam 306 closes normally open switch 307 in the reversing circuit line I of motor 231. This moves the rollers 261 out of wedge relationship to the position shown in FIGURE 20 and slightly rotates gear 279 relative to wear plates 282. Immediately when the inward movement of ram 187 to eject the biscuit portion is completed, timer cam 2% closes switch 297 to energize the clutch 268 momentarily for a purpose to be presently described and brake 284 is, of course, deenergized or released by pressure switch 210 when the force built up in cylinder 20% over the normal pressure carried is dissipated. With member 254 moving clockwisely and clutch 268 couplying gears 27% and 264, the rollers 2&1 are displace-:1 clockwisely and wedged between members 254 and 255 so that shaft 243 is driven clockwisely as in FIGURE 21. When the clutch 268 is energized, elements 267a and 267 are magnetically coupled 'so that the counterclockwise rotation of shaft 236 is transferred to the spider 263 as clockwise rotation. This clockwise rotation, for an instant before clutch 268 is immediately deenergized by cam 295, while member 255 is stationary, moves the rollers 261 into clockwisely wedged position. The clutch 280 slips to permit this and slips during the time members 254 and 255 are coupled to compensate for the difference in gear ratio of gears 2'79, 244, and 245, 246. With shaft 243 driven clockwisely, rack 201 is accordingly retracted outwardly and the inner wall of the piston chamber 206 engages the outer, enlarged end 199a of slide 190 to carry shot plunger 187 outwardly. With outward movement of rack 201, rack 226 is forced upwardly and piston 227 compresses the air inside cylinder 225 to store energy therein for the next inward stroke of the shot plunger. At the time that conventional pressure switch 295 is activated by the buildup of a predetermined pressure in cylinder 225, motor 231 is deenergized and brake 204 is applied. Pressure switch 2%; has normally closed contacts 295a in circuit line I and normally open contacts 295]; in circuit line 11. The reason that the closing of contacts 2951) energizes the brake is because timer cam 308 has closed normally open switch 309 in the motor 218 reversing circuit 11 for a length of time just sufficient to move plate 304 out of contact with normally closed switch 305, which permits switch 305 to close. This occurs just before pressure switch 295 is activated. Timer cam 308 then permits switch 300 to open again prior to closing it again at the end of the cycle after rack 201 has been brought back to outermost position. When switch sea is again closed, cam 221 is moved clockwisely and cam face 223 engages plate 22 and movesthe slide 199 outwardly. It will be noted that there is sutficient axial length in piston chamber 2% for this movement, which opens the pouring spout 1%, to take place. When cam 221 has moved clockwisely the requisite distance, timer cam 3% permits switch 3% to open again prior to commencement of the next cycle of operation. If the push button 285 is then held in depressed position, the cycle as described will be repeated.

The air release valve 310 shown in FIGURE 13 is a normally closed valve which can be opened to adjust the supply of pressure fluid in cylinder 225. It will be noted that cylinder 225 is threaded at its upper end as at 311 and is closed by a cooperatively threaded cap member 312. A threaded post 313 adjustably mounted by cap plate 312 carries a plate 314 which tightly seals the chamber. However, an opening 315 is provided in plate 314 and an opening 316 is provided in the threaded member 313 in communication with a line 317 which communicates with valve 316 and pressure witch 295. In this way, the force exerted by the rack 201 to force the shot into the die cavity can be adjusted and, if desired for purposes of demonstration, the working pressure in air cylinder 225 can be reduced to atmospheric pressure so that the various elements may be jogged through the cycle. The control apparatus which will permit this is not shown in the instant application since it forms no part of the present invention. However, it will be understood that it can be connected in a conventional manner. Similarly, the conduit 209 which leads to a source of air supply has a check valve 318 which prevents the escape of air from the cylinder 2% while permitting the admission of air from an air supply source if desired.

The pressure switches 210 and 295 are switches which, when the pressure to which they are exposed reaches a certain predetermined set value, operate to either open or close one or more switches. They are conventional and may be of the Eagle type manufactured by Eagle Manufacturing Co. As illustrated by the representation of the switch for operating contacts 295a in circuit 1 of FIG- URE 22, each pressure switch comprises a cylinder 31% with which the air conduit (307 in this instance) communicates. A plunger 320 in the cylinder has a plunger head 321 which is moved into engagement with and opens or closes the adjacent switch or switches when the air'in the cylinder 307 is pressurized to an extent sufiicient to overcome spring 322. The resistant force of spring 322 is carefully gauged such that a switch is actuated when a predetermined air pressure is reached and the same plunger 321 can operate switches 295a and 2951) 'or 21611 and 21011.

The brake is a conventional Fawick electric brake manufactured by Fawick Corp., of Cleveland, Ohio. The brake 284 is shown schematically in FIGURE 22 as having an energizing coil 323 for moving it into braked engagement with shaft 243. The brake is preferably spring returned as by springs 324.

In FIGURE 13 rods 325 having head ends 325a are shown connected with plate 224. The rodsfreely pass through the front wall 326 of-housing 189 and the enlarged ends 325a provide a positive limit to the forward movement of plunger 187. Thus the forward stroke of plunger 187 is arrested it the shot of material is insufficient to form a biscuit and after the biscuit is ejected so that the dies are prevented from possible damage.

FIGURE 24 indicates a modification of the invention in which resilient metal bellows members 327 are used in place of the piston and return spring arrangements emformed by the bellows members-327, bores 332 through member 19, and chambers 333 in a cylinder head plate 334 which is secured by bolts 334 to member 19. When fluid under pressure is forced into cylinders 328 pistons 329 move outwardly and bellows members 327 are expanded. However, when the fluid is permitted to return to chamber 127, the bellows members are sufficiently resilient to return the pistons 32? to initial position. Guide pins 335 insurelinear movement of the pistons 329.

It is to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in the various elements to achieve like results without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In die casting apparatus and the like; relatively mov able, material forming members providing a die cavity, one of said members having a passage leading to said cavity; a shot injection member movable inwardly to force a supply of material through said passage to the cavity; nonfiuid pressure, mechanical motor means; compressed fluid pressure source means operatively coupled with said shot injection member for blasting said shot injection inwardly in a path to force material in said passage into said cavity; and means operatively associated with said motor means for operatively coupling the motor means and shot injection member at a time when the shot injection member nears the end of its inward travel for applying a constant pressure on said shot injection member at the end of the stroke. 7

2. In die casting apparatus and the like; an openable die member assembly providing a die cavity having a material injecting passage leading to said cavity; means having an opening remote from said cavity for supplying material to said passage; a ram movable forwardly in said passage from a position outwardly of said opening to forcea supply of material to said cavity; first motor means; means driven thereby for moving said ram forwardly past said opening and thence disengaging therefrom; second motor means furnishing the power for shot injecting movement of said ram at a rapid speed once it has been moved relatively slowly past said opening by said first motor means and for returning the ram; a projecting member connected with said ram; said first motor means connecting with a pair of circumferentially spaced surfaces engageable with said projecting member to move said ram forwardly past said material supply opening and rearwardly to clear said material supply opening; and vmeans for operating said first motor means in timed sequence with said second motor means.

3. In die casting apparatus and the like; an openable die member assembly providing a die cavity having a material injecting passage leading to said cavity; means having an opening remote from said cavity for supplying material to said passage; a ram movable forwardly in said passage from a position outwardly of said opening to force a supply of material to said cavity; first electric motor means; means driven thereby operatively engaging said ram for moving said ram forwardly past said opening and thence operatively disengaging therefrom; and second electric motor means furnishing the power for shot injecting movement of said ram at a rapid speed onceit has been moved-relatively slowly past said opening by said first electric motor meanszand for returning thev ram at a slower speed. a

4. 'The combination defined in claim 3 in which means is provided for starting said second motor means prior to the time said ram is moved past said opening but preventing its driving engagement with the ram until after the ram is moved past said opening;

5. In die casting apparatus and the like; an opena-ble die member assembly having a the cavity and a material injecting member leading thereto having a material supply opening remote from the cavity; a ram reciprocable 

3. IN DIE CASTING APPARATUS AND THE LIKE; AN OPENABLE DIE MEMBER ASSEMBLY PROVIDING A DIE CAVITY HAVING A MATERIAL INJECTING PASSAGE LEADING TO SAID CAVITY; MEANS HAVING AN OPENING REMOTE FROM SAID CAVITY FOR SUPPLYING MATERIAL TO SAID PASSAGE; A RAM MOVABLE FORWARDLY IN SAID PASSAGE FROM A POSITION OUTWARDLY OF SAID OPENING TO FORCE A SUPPLY OF MATERIAL TO SAID CAVITY; FIRST ELECTRIC MOTOR MEANS; MEANS DRIVEN THEREBY OPERATIVELY ENGAGING SAID RAM FOR MOVING SAID RAM FORWARDLY PAST SAID OPENING AND THENCE OPERATIVELY DISENGAGING THEREFROM; AND SECOND ELECTRIC MOTOR MEANS FURNISHING THE POWER FOR SHOT INJECTING MOVEMENT OF SAID RAM AT A RAPID SPEED ONCE IT HAS BEEN MOVED RELATIVELY SLOWLY PAST SAID OPENING BY SAID FIRST ELECTRIC MOTOR MEANS AND FOR RETURNING THE RAM AT A SLOWER SPEED.
 12. APPARATUS FOR DRIVING A DIE CASTING MACHINE SHOT INPECTING PLUNGER COMPRISING; MOTOR MEANS; A DRIVE SHAFT; A PAIR OF DISENGAGEABLE MEMBERS BETWEEN SAID MOTOR MEANS AND SHAFT COMPRISING PERIPHERALLY SPACED SURFACES, ONE OF WHICH IS GENERALLY POLYGONAL AND THE OTHER GENERALLY ANNULAR, TO PROVIDE SPACES OF NORMAL WIDTH BETWEEN SAID SURFACES AND SPACES OF DECREASED WIDTH; WEDGE MEMBERS OF A DIAMETER LESS THAN THE NORMAL SPACES BETWEEN SAID SURFACES BUT GREATER THAN THE DECREASED SPACES BETWEEN THEM; A POWER MEMBER CONNECTED WITH SAID DRIVE SHAFT FOR DRIVING IT AT A HIGH RATE OF SPEED; MEANS CONTROLLING SAID WEDGE MEMBERS TO MOVE THEM TO WEDGED POSITION TO ENGAGE SAID MOTOR MEANS AND SHAFT ONLY AFTER THE FORCE OF THE POWER MEMBER IS SOMEWHAT EXPENDED AND SAID HIGH RATE OF SPEED HAS ABATED; AND SELECTIVELY OPERATIVE MEANS FOR OPERATING SAID MEANS CONTROLLING SAID WEDGE MEMBERS. 